Method and device for sensor level image distortion abatement

Abstract

A method, apparatus and software product for image processing using meta-data obtained by sampling the pixels or pixel regions of the image sensor array during the acquisition of the image. A performance enhancement is achieved by applying (non-linear) signal processing methods to the individual pixels or pixel regions of the array during image formation. The in-situ signal processing method described leverage knowledge of the image formation process to improve the signal quality of the pixels in the array. The present method, apparatus and software product may be used for post acquisition processing of the image or for processing during or immediately following acquisition of the image. Embodiments of the method mitigate noise, blur, and low contrast distortions in digital imaging arrays. Hardware and software embodiments are also presented.

1 . A digital imaging system, comprising: 
 an image sensor array having an output for image data;    an optical system mounted to direct electromagnetic energy onto said image sensor array; and    an image processor connected to said image sensor array, said image processor operable to monitor image signal accumulation during acquisition of an image by said image sensor array so as to determine a temporal change in signal accumulation, said image processor applying information obtained during acquisition of an image relating to said temporal change to process image data output by said image sensor array, said image processor providing processed image data including image data processed with information obtained during said monitoring of the image signal accumulation.    
   
   
       2 . A digital imaging system as claimed in  claim 1 , wherein said image processor obtains image accumulation data for a plurality of pixels or pixel areas in a region during image accumulation and said image processor processes image data in said region.  
   
   
       3 . A digital imaging system as claimed in  claim 1 , further comprising: a memory connected to store image accumulation values obtained during image accumulation.  
   
   
       4 . A digital imaging system as claimed in  claim 1 , wherein said image processor includes a sensor accelerator connected to said image sensor array.  
   
   
       5 . A digital imaging system as claimed in  claim 1 , wherein said image processor is operable to determine a change in image accumulation rate in at least one pixel or pixel region of said image sensor array during acquisition of the image.  
   
   
       6 . A digital imaging system as claimed in  claim 5 , wherein said change in image accumulation rate corresponds to movement of at least one object in an image frame of the image during acquisition of the image and said processor is operable to at least decrease blur in the image attributable to said movement.  
   
   
       7 . A digital imaging system as claimed in  claim 5 , wherein said change in image accumulation rate corresponds to saturation of a pixel or pixel region during acquisition of the image and said processor is operable to at least reduce effects of said saturation in the image.  
   
   
       8 . A digital imaging system as claimed in  claim 1 , wherein said processor is operable to obtain image level data from said image sensor array a plurality of times during acquisition of the image.  
   
   
       9 . A digital imaging system as claimed in  claim 1 , wherein said image sensor array is a light sensitive array.  
   
   
       10 . A digital imaging system as claimed in  claim 1 , wherein said image sensor array is an infra-red sensitive array.  
   
   
       11 . A method for processing an image, comprising the steps of: 
 acquiring the image by an array of image sensors over an image acquisition time;    reading image accumulation values of at least ones of said image sensors during said image acquisition time to obtain information regarding the image accumulation;    processing image data acquired in said acquiring step using information regarding the image accumulation obtained in said reading step; and    outputting processed image data.    
   
   
       12 . A method as claimed in  claim 11 , further comprising the step of: 
 outputting the image accumulation information.    
   
   
       13 . A method as claimed in  claim 11 , wherein said step of reading image accumulation includes reading a rate of image accumulation during the image acquisition time.  
   
   
       14 . A method as claimed in  claim 11 , wherein said processing of the image data acquired during said acquiring step identifies a temporal event during the image acquisition time.  
   
   
       15 . A method as claimed in  claim 11 , further comprising the steps of: 
 storing information obtained in said reading steps at least to an end of said image acquisition time; and    using said stored information during said processing step.    
   
   
       16 . A method as claimed in  claim 11 , wherein said step of processing includes: 
 deriving an intensity value of at least one pixel or pixel region; and    comparing the derivative obtained in said deriving step of a predetermined threshold value.    
   
   
       17 . A method as claimed in  claim 11 , further comprising the step of: 
 halting updating of a pixel or pixel region value upon detection of a temporal event during the image acquisition time.    
   
   
       18 . A method for obtaining an image, comprising the steps of: 
 acquiring an image by a digital imaging system;    sampling pixels or pixel regions of the digital imaging system during acquisition of the image;    determining a presence of a predetermined characteristic in image signal build up during acquisition of the image;    processing image signals of said image; and    outputting image data including said processed signals of said processing step.    
   
   
       19 . A method as claimed in  claim 18 , wherein said predetermined characteristic is a temporal event during acquisition of the image.  
   
   
       20 . A method as claimed in  claim 18 , wherein said temporal event is a change in accumulation rate.  
   
   
       21 . A method as claimed in  claim 18 , further comprising the step of: 
 defining regions of the image in which the change in image signal build up occurred; and 
 wherein said processing step includes processing image signals of said regions of said defining step.  
   
   
   
       22 . A method as claimed in  claim 18 , further comprising the step of: 
 recording values of pixels or pixel regions at instances during the image acquisition.    
   
   
       23 . A software product for image processing, comprising: 
 software stored in a memory and being capable of running on a computer system, the software being programmed to perform the steps of:    reading image data;    reading image accumulation values of at least ones of said image sensors obtained during said image acquisition time to obtain information regarding the image accumulation;    processing image data acquired in said acquiring step using information regarding the image accumulation obtained in said reading image accumulation values step; and    outputting processed image data.    
   
   
       24 . A software product as claimed in  claim 23 , wherein said step of reading image accumulation values by the software is performed during acquisition of the image.  
   
   
       25 . A software product as claimed in  claim 23 , wherein said step of reading image accumulation values by the software is performed after acquisition of the image.  
   
   
       26 . A digital image processing system, comprising: 
 a graphical user interface on an interface computer;    a storage device on which is stored image data and metadata corresponding to said image data;    image processing software on a processing computer that processes the image data to output a processed image using the meta-data.    
   
   
       27 . A method for image acquisition, comprising the steps of: 
 acquiring an image using a digital imaging system;    sensing pixels during said step of acquiring the image;    comparing an intensity of the pixels to a predetermined threshold during said step of acquiring the image;    halting image formation at pixels that exceed said predetermined threshold while continuing image formation at pixels that have not reached said predetermined threshold;    completing said image acquisition; and    outputting data of said image.    
   
   
       28 . A method as claimed in  claim 27 , wherein said intensity of the pixels is a time derivative of an intensity value.  
   
   
       29 . A method as claimed in  claim 27 , wherein said predetermined threshold is spatially and temporally adapted.  
   
   
       30 . A method for image acquisition, comprising the steps of: 
 acquiring an image using a digital imaging system;    sensing pixels during said step of acquiring the image;    determining the pixels that are imaging a moving portion of the image during said step of acquiring the image;    modifying image formation at pixels that are determined to be imaging the moving portion while continuing image formation at pixels that have not been determined to be imaging the moving portion;    completing said image acquisition; and    outputting data of said image.    
   
   
       31 . A method for image acquisition, comprising the steps of: 
 acquiring an image using a digital imaging system;    sensing pixels during said step of acquiring the image;    determining the pixels that are imaging a moving portion of the image during said step of acquiring the image;    halting image formation at pixels that are determined to be imaging the moving portion while continuing image formation at pixels that have not been determined to be imaging the moving portion;    completing said image acquisition; and    outputting data of said image.